The equine influenza is a very contagious viral
disease which only affects equids. This virus generates an acute
infection of epithelium of the higher respiratory tracts and lungs.
It is generally without complications, but infections bacteria can
sometimes cause more serious complications.
The donkeys are particularly sensitive to this virus, and show clinical
signs more severe then that of the horse.

Contamination

The virus is very easily transmitted between equids by air, for
several kilometers by the wind. The virus can also be transmitted
by various objects like feeding troughs, halters...

After inhalation, the influenza virus develops very quickly in
the cells of the respiratory tract, thus causing the death of the
infected cells. It follows from there a reduction of the animals
immune defence system, thus facilitating the multiplication of many
bacteria. The disease can also develop towards disease of bacterial
origins like strangles.

Symptoms

The incubation period is short (1 to 3 days), and the first symptoms
appear suddenly:
 high fever for 1 to 5 days
 dry coughing fit's which can persist several weeks
 nasal discharge
 lost of appetite
 lymphopaenia

The donkey can have a very high fever for 2 to 3 days after the
first symptoms of the illness, and sometimes longer in duration.
Then, the cough becomes loose, and nasal discharge becomes thicker,
white or yellowish. Generally, the symptoms disappear in about fifteen
days without after-effects.

Bacterial complications can appear: bronchitis, pharyngitis, pleurisy,
infection of the gutturals pockets and myocarditis (inflammation
of the cardiac muscle). It can result in death for the older animals
or very young foals.

Prevention - Treatment

The equine influenza is very contagious so the sick donkey will
have to be isolated for at least two weeks. It will stay in a ventilated
stable without dust at least for a month (1 day of fever = 1 week
of rest) in order to find its full respiratory capacity. To begin
training to soon could result in bacterial complications and chronic
respiratory obstructive diseases.

A vaccination is available, 2 doses of vaccine are initially given
4 to 6 weeks apart followed by boosters at 6 monthly intervals and
at least every year.

Vaccination is often incomplete and vaccinated donkeys can as a
result contract the virus. But the vaccinated animals will avoid
the major clinical signs of the disease, and will be able to work
after a shorter convalescence.